Western union money transfer?

I am going to Mexico City for a trip. I am a US citizen, but I speak Spanish and I want to transfer money via Western Union to Elektra, but I am worried since I heard that they may give you issues when it comes to picking up the money in Mexico City because of your identity or something of that nature can anybody confirm from experience what do I need exactly as a US citizen to successfully transfer and receive the money from Elektra?